Metallurgical Control of Fatigue Crack Growth in High-Strength Aluminum Alloys
Final rept. 1 Jan-30 Dec 1971
BATTELLE COLUMBUS DIV OH
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The results of 22 different investigations of cyclic crack growth, principally on the 2024-T3 and 7075-T6 alloys, but including results for unalloyed and other 2-, 5-, 6-, and 7-thousand series alloys, were examined and compiled with a view to separating metallurgical effects from other factors. The various crack growth measurements show good agreement when the comparisons involve the same R-value, environment and cyclic frequency. Both the 2024-T3 and 7075-T6 alloy can display widely different rates of Both the 2024-T3 and 7075-T6 alloy can display widely different rates of growth for the same delta K-value. Crack growth rate-delta K measurements have also been converted into S-N curves for cracked members. These curves illustrate the influence of flaw size, stress range, R and K sub c on the cyclic life of the 7075-T6 and 2024-T3 grades.
- Metallurgy and Metallography